caa a22 4500 475742575 CHVBK 20180406123503.0 cr unu---uuuuu 170329e20000601xx s 000 0 eng 10.1007/s002400000108 doi (NATIONALLICENCE)springer-10.1007/s002400000108 Nucleation and aggregation of calcium oxalate in whole urine; spectrophotometric sedimentation analysis: a new approach to study the aggregation of calcium oxalate dihydrate [Elektronische Daten] [J. M. Baumann, B. Affolter, U. Caprez, D. Lauper, F. Maier, H. P. Siegrist, T. Zysset] Spectrophotometric and scanning electron microscopic (SEM) studies of oxalate-induced crystallization have been performed in whole urine with and without continuous magnetic stirring and before and after millipore filtration of urine. With continuous stirring, preferential nucleation was observed and this followed second order kinetics. Important crystal aggregation only occurred after an oxalate load above 1 mmol/l and without stirring. Under these conditions and at an ionic calcium concentration of 2 mmol/l, single crystals and aggregates of calcium oxalate dihydrate and monohydrate of well defined sizes were produced. Single dihydrates, their aggregates and the other particles could be distinguished by their significantly different sedimentation rates. From sedimentation curves an aggregation ratio for calcium oxalate dihydrate (aggregated/total dihydrate particles) was extrapolated. Millipore filtration removing important urinary macromolecules increased this aggregation ratio as well as the size of the aggregates on SEM pictures. Springer-Verlag Berlin Heidelberg, 2000 Key words Urolithiasis nationallicence Calcium oxalate nationallicence Crystallization nationallicence Aggregation nationallicence Baumann J. M. Stone Research Center Violab, Unterer Quai 92, 2502 Biel, Switzerland Tel.: 0041 32323 3885; Fax: 0041 32323 3886, CH aut Affolter B. Stone Research Center Violab, Unterer Quai 92, 2502 Biel, Switzerland Tel.: 0041 32323 3885; Fax: 0041 32323 3886, CH aut Caprez U. Stone Research Center Violab, Unterer Quai 92, 2502 Biel, Switzerland Tel.: 0041 32323 3885; Fax: 0041 32323 3886, CH aut Lauper D. Materials Laboratory, Manufacture des montres ROLEX SA, Biel, Switzerland, CH aut Maier F. Materials Laboratory, Manufacture des montres ROLEX SA, Biel, Switzerland, CH aut Siegrist H. P. Stone Research Center Violab, Unterer Quai 92, 2502 Biel, Switzerland Tel.: 0041 32323 3885; Fax: 0041 32323 3886, CH aut Zysset T. Stone Research Center Violab, Unterer Quai 92, 2502 Biel, Switzerland Tel.: 0041 32323 3885; Fax: 0041 32323 3886, CH aut https://doi.org/10.1007/s002400000108 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/s002400000108 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Baumann J. M. Stone Research Center Violab, Unterer Quai 92, 2502 Biel, Switzerland Tel.: 0041 32323 3885; Fax: 0041 32323 3886, CH aut NATIONALLICENCE 700 1- Affolter B. Stone Research Center Violab, Unterer Quai 92, 2502 Biel, Switzerland Tel.: 0041 32323 3885; Fax: 0041 32323 3886, CH aut NATIONALLICENCE 700 1- Caprez U. Stone Research Center Violab, Unterer Quai 92, 2502 Biel, Switzerland Tel.: 0041 32323 3885; Fax: 0041 32323 3886, CH aut NATIONALLICENCE 700 1- Lauper D. Materials Laboratory, Manufacture des montres ROLEX SA, Biel, Switzerland, CH aut NATIONALLICENCE 700 1- Maier F. Materials Laboratory, Manufacture des montres ROLEX SA, Biel, Switzerland, CH aut NATIONALLICENCE 700 1- Siegrist H. P. Stone Research Center Violab, Unterer Quai 92, 2502 Biel, Switzerland Tel.: 0041 32323 3885; Fax: 0041 32323 3886, CH aut NATIONALLICENCE 700 1- Zysset T. Stone Research Center Violab, Unterer Quai 92, 2502 Biel, Switzerland Tel.: 0041 32323 3885; Fax: 0041 32323 3886, CH aut Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer